Convert British Thermal Units to Kilotons of TNT
Convert British Thermal Units (BTU) to Kilotons of TNT (kt(TNT)) instantly and accurately.
Conversion Formula
kt(TNT) = BTU × 2.521644007e-10
About British Thermal Units
A British Thermal Unit (BTU) - the heat to raise 1 lb of water by 1°F - equals exactly 1,055.05585262 J. It dominates US HVAC: room air conditioners are rated in BTU/h (5,000-24,000 BTU/h = 1.5-7.0 kW); one ton of refrigeration is exactly 12,000 BTU/h. Natural gas is billed in therms (100,000 BTU) in the US. Higher heating values: natural gas ~1,020-1,050 BTU/ft³; No. 2 fuel oil ~138,700 BTU/US gal; propane ~91,500 BTU/US gal. 1 BTU = 1,055.06 J = 252.164 cal = 0.29307 Wh.
About Kilotons of TNT
A kiloton of TNT (kt(TNT)) = 10³ tons of TNT = exactly 4.184 TJ. It is the standard unit for sub-megaton nuclear weapon yields. Hiroshima's Little Boy: ~12-18 kt; Nagasaki's Fat Man: ~19-23 kt. The W88 warhead (Trident II) is ~475 kt; the W76 is ~100 kt. The Beirut port explosion (2020): estimated 0.5-1.1 kt. A magnitude 5.0 earthquake releases ~0.5-2 kt of seismic energy. A kiloton blast creates a fireball ~90-100 m radius and a lethal thermal radius of ~1-2 km. 1 kt(TNT) = 4.184 TJ = 1,162.8 MWh.
Quick Reference Table
| British Thermal Units (BTU) | Kilotons of TNT (kt(TNT)) |
|---|---|
| 1 BTU | 2.522 × 10-10 kt(TNT) |
| 2 BTU | 5.043 × 10-10 kt(TNT) |
| 5 BTU | 1.261 × 10-9 kt(TNT) |
| 10 BTU | 2.522 × 10-9 kt(TNT) |
| 25 BTU | 6.304 × 10-9 kt(TNT) |
| 50 BTU | 1.261 × 10-8 kt(TNT) |
| 100 BTU | 2.522 × 10-8 kt(TNT) |